· by superage.bsky.social ·17h ago · view on bsky.app ↗

VO2 max in 30 seconds: My take: it is the cleanest fitness biomarker for aerobic capacity, the max oxygen used during hard effort. Zone 2 builds the base behind it.

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Anime-style runner training at an easy pace with smartwatch fitness metrics visible.

1 comments — live from bluesky

SuperAge · 0 · 17h ago

Why it matters for biological age: higher VO2 max tracks with better cardiorespiratory reserve. Reserve = spare capacity when life adds stress. A 1-MET gain equals ~3.5 ml/kg/min.

SuperAge · 0 · 17h ago

Typical ranges vary by age and sex. Ages 40-49: men ~30-44 ml/kg/min, women ~23-37. Elite endurance athletes can sit above 60; sedentary adults can sit below 25.

SuperAge · 0 · 17h ago

Main levers: sleep consistency, aerobic volume, intervals, strength work, and diet quality. Zone 2 means easy enough to talk, hard enough to need focus.

SuperAge · 0 · 17h ago

Apple Watch estimates Cardio Fitness from heart rate + movement during outdoor walks/runs/hikes. It is not lab VO2 max, but the trend line is useful.

SuperAge · 0 · 17h ago

Common mistake: treating 1 low reading as identity. VO2 max is noisy. Heat, fatigue, route, GPS, caffeine, and wrist fit can shift estimates.

SuperAge · 0 · 17h ago

Zone 2 targets mitochondrial density: more cellular power plants per muscle fiber. That supports better fat oxidation at submaximal intensity.

SuperAge · 0 · 17h ago

Related marker: resting heart rate. When aerobic fitness improves, the heart pumps more per beat, so resting HR can drift lower over months.

SuperAge · 0 · 17h ago

Related marker: HRV. HRV = beat-to-beat timing variation. It reflects recovery load; rising VO2 max with collapsing HRV suggests the dose is too high.

SuperAge · 0 · 17h ago

Related marker: lactate threshold. Threshold = intensity where lactate rises fast. Zone 2 sits below it, building durability without maximal strain.

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